Am I Destined to Be Slow Because of Asthma?

I am a 25-year-old severe lifelong asthmatic who took up running several years ago to help with my breathing and overall health. Now that I've started running events, I have noticed one problem: I can't get any faster. I usually only run about 10-15 miles per week, but even after regular training for my last half marathon (20+ miles per week), I couldn't make it faster than 11 minutes/mile on average. I'm 5'2" and 138 pounds, which I know isn't svelte, but I've seen people heavier than me run faster. It's not like I want to compete, but I can't even do one 9-minute mile! My asthma is never going away, and I've maxed out my options as far as medications (I take Advair, Singulair and a quick-rescue inhaler taken 15 minutes before every run). I don't have asthma "attacks" when I run, but I am out of breath whenever I try to speed up my pace. Is there anything I can do to improve my breathing while running? Would losing weight help? Or am I destined to be slow forever thanks to my less-than-great lungs? -- Jessica

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